# Nathan J. Williams 2007-04-26:
> David Young <dyoung@pobox.com> writes:
> > On Fri, Apr 27, 2007 at 12:48:33AM +0900, ITOH Yasufumi wrote:
> >>  - caddr_t removal, expecting it will soon be reverted :D
> >
> > It will not be reverted.
> >
> >>  - volatiles in DMA structure, since it should not be needed
> >>    with proper bus_dmamap_sync(9)s
> >
> > Volatiles are needed on shared data structures, regardless of whether
> > you use bus_dmamap_sync() properly.
> 
> Are you talking about data structures shared between the kernel top
> half and bottom half?

Shared with device I'd guess from previous context of discussion.

> If so, I think I know what you're saying here, but I'd like to say that
> I consider this use of volatile, while expedient, to be a problematic

Why problematic?

> workaround for a deficient spl() implementation.

How could be spl() implemented to avoid the need for volatiles?

	-- Jachym